1. Field of the Invention
This invention relates to a reader-printer which performs the function of projecting an image recorded in a microfilm on a screen and the function of printing this image. More particularly, this invention relates to a reader-printer so configured to prevent the margin of the microfilm from being recoded in the form of a black frame on the recording paper.
2. Description of the Prior Arts
The microfilm on the ordinary run has a margin around an image recorded therein. When a photosensitive member is exposed to such an image and a corresponding copied image is formed on a recording paper in the conventional reader-printer, therefore, the margin around the image manifests itself as a black frame on the recording paper.
As one solution for this problem, Japanese Patent Application Laid-Open No. SHO 61(1986)-134,749 discloses a reader-printer which is provided within the path of the light projected through an image with a light-intercepting member retractable in the axial direction of a photosensitive drum and further provided on the light-intercepting member with a light quantity sensor for control of the motion of the light-intercepting member necessary for shielding the region outside the image from the projected light. The reader-printer disclosed by this patent specification, however, necessitates the light quantity sensor for the detection of the boundary between the image and the margin and, therefore, suffers an increase in the number of component parts and proves disadvantageous in terms of cost and space.
U.S. Pat. No. 4,708,464 discloses a reader-printer which is provided within the path of the light projected through an image with a light-intercepting member retractable in the axial direction of a photosensitive drum and which, owing to the light-intercepting member, intercepts the path of the light projected through an unnecessary region of an image and permits copying only a part of the image. The reader-printer disclosed in this U.S. patent specification, however, entails an intricate operation because the operator is required to designate the range of the image and move the light-intercepting member accordingly.